1. Field
The following description relates generally to wireless network communications, and more particularly to controlling transmission control protocol (TCP) transmissions in handover.
2. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), evolution data optimized (EV-DO), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Further, communications between mobile devices and base stations may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or base stations with other base stations) in peer-to-peer wireless network configurations.
In addition, a device can handover communications among various base stations, which can be of different radio access technologies (RAT), to provide a user thereof with a seamless network access experience. The device can also be implemented with transmission control protocol (TCP) congestion control functionality to allow for resizing a TCP window size to control data rate at the device and/or transmitter based on aspects of received packets. For example, if packets are being transmitted quicker than the device can receive and process the packets, this can be determined based at least in part on detecting out-of-sequence packets (e.g., according to a sequence number related to the received packets). The TCP layer of the device can determine the out-of-sequence packets and can indicate congestion to a base station or other transmitter by communicating one or more duplicated acknowledgements (ACK) over a hybrid automatic repeat/request (HARQ) or similar feedback channel, and the transmitter can accordingly reduce the TCP window size (e.g., to half the size, which can be known as Fast Recovery). During device handover, there can be cases where the device temporarily receives out-of-sequence TCP packets; however, reducing the window size at the transmitter may not be the desired behavior.